Hydraulic power system for synchronous operation of press elements



R. E. SHEAHAN 2,602,246 HYDRAULIC POWER SYSTEM FOR SYNCHRONOUS OPERATION OF PRESS ELEMENTS July 8, 1952 2 Sl-IEETS-SI-1EET 1 Filed Aug. 5, 1949 2+2 Ihverwtom Robert E. She ahan,

L ia I E His Attovn y.

.Fufiy 8 1952 R. E. SHEAHAN 2,592,245

HYDRAULIC POWER SYSTEM FOR SYNCHRONOUS OPERATION OF PPEss ELEMENTS 2 SHEETS--SHEET 2 Filed Aug. 5, 1949 Inventor: Robert E. Sheahan,

W H i s Attorney.

Patented July 8, 1952 o RoNoUs' ELEMENTS OPERATION OF PRESS Robert E. Sheahan, South Euclid, Ohio, assignor to General Electric Company, a corporation of New York Application August 5 1949, Serial No. 108,837

21 Claims.

This invention relates to an improved hydraulic power system for operating in timed relationship, devices such as the mutually cooperating press elements in domestic ironing machines.

A flat plate ironing machine, which has been selected as typical of a machine with which the present invention may advantageously be used,

is shown in the Wardwell, Jr, Patent No. 2,135,266 granted November 1, 1938 for Ironing Press and assigned to the assignee of the present application. The i'roner disclosed therein is es-. sentially a domestic type machine, in which. a

flat padded buckfis the surface on which the dampened clothes are placed, and a heated shoe supported by a, carriage pivoted to the frame structure is arranged to be manually drawn forwardly to a position overlying the buck in parallelism therewith. Thereupon, the openator actuates a mechanism effective to drive the buck upwardly to press the clothes against the surface of the heated shoe.

I It is a particular object of the present invention to provide an 'improvedhydraulic power system for automatically operating press devices in timed sequence, therebyas exemplified in such ironing machines-relieving the operator of the manual labor of operating the shoe by establish! ing an automatic coordination of movements of the shoe and the buck.

t It is another object of the invention. to provide an improved means for operatingpress-devices as aforesaid, incorporating simple, efiec tive safety-devices to allow the operator manually to hold one of the work devices against ful1 movement,'notwithstanding the relatively high hydraulic pressure in the system created by the continued operation of thehydraulic pressure generator and without damage to the structure or the imposition of excessive strains thereon.

It is a further object of the invention to provide an improved hydraulically actuated ironing machine of the aforesaid type in which the .operator may manually stop the movement of the sh e toward i s s nsno it n and sl w the upward movement of the buck, even though the hydraulic power means remains in operation.

It is also an object of the invention, to provide an automatic ironing machine or the likeghaving means whereby a, desired speed of movement of the shoe carriage relative to the buck may-be easily established. 1

It is an object of the invention to-provide means for preventing a premature rise of the buck, thereby insuring the proper coordination of the buck and shoe. v

'. therein.

It is yet another object of the invention to provide a simple and effective hydraulic mechanism for automatically operating the buck and the shoe of an ironing machine, having relatively few working parts and being capable of operation over long periods with freedom from mechanical difficulties.

A presently preferred embodiment of my improved hydraulic press actuating mechanism in cludes a cylinder having combined piston and hydraulic pressure generation means, a second cylinder, and a main conduit through which fluid under pressure flows from the first to the second cylinder to exert pressure against a piston The. respective pistons are mechanically connectedto a work device to operate the same; in an ironing machine, they combined piston and pressure generator may be attached to the buck, and the piston in the second cylinder arranged to operate the shoe arm. Means are provided to return each piston to a home" position in which the buck and shoe are retracted. In such position, a nozzle valve comprising the discharge from the pressure generator is seated with respect to an outflow port at the base or the cylinder. Said port provides the inlet to the aforesaid main conduit. I relate the nozzle valve area and area of the second piston to each other and to the hydraulic pressure generated within the first cylinder so that with the nozzle valve seated at the commencement of operation the pressure causes the second piston to move, thus raising the shoe, but is ineffective to raise the buck until the shoe arm has completed its travel, as determined by suitable stop means. Then, the reaction of the hydraulic pressure against the nozzle valve will lift the associated piston to unseat the valve, whereupon full pressure becomes available against the entire area of the piston, and the buck rises smoothly and rapidly. V

The safety features and insured synchronism mentioned among the objects are provided by a supplemental conduit extending between the first and second cylinders; specifically, the conduit communicates with the first cylinder at the upstream side of the nozzle valve seat, and with the second cylinder sufliciently upwardly of itswall to be closed by the piston therein only as "the same approaches completion of its stroke. With this arrangement, the operator maygrasp the rising shoe and hold it against further movement even though the hydraulic generator isstilhopcrating, I01 as soon as the shoe arm is stopped and the buck piston risesslightly to unseat' the nozzle valve, the pressure in the buck cylinder will expend itself through the supplemental conduit to enter the second cylinder above its piston. In normal operation, the closing of the conduit as the shoe arm piston substantially completes its normal stroke makes operating pressure available in the buck cylinder as aforesaid.

Other features and advantages will be apparent from the following detailed description of the invention and the accompanying drawings in which a presently preferred embodiment has been selected for purpose of illustration.

In the drawings, Fig. 1 is a front elevational View of an ironing machine embodying the present invention, the shoe being shown in its rearward position so as to expose the surface of the buck; Fig. 2 is a side elevation, partially in section along lines 22 of Fig. 1, the pressing position of the buck and shoe being shown in dotted line; Fig. 3 is a rear elevation showing the association of the buck and shoe actuating cylinders, said figure being in section on lines 3-3 of Fig. 2; Fig. 4 is a side elevation in section taken through the lower portion of the buck cylinder and through the shoe cylinder, and particularly showing the fluid passages interconnecting the buck and shoe cylinders.

Figs. 5 and 6 are views similar to Fig. 4, being in somewhat schematic form for simplification and showing the operation of the fluid pressure at the commencement and end of the pressing phase; Fig. '7 is a perspective view of the impeller rotor; Fig. 8 is a schematic wiring diagram showing one means of controlling the speed of shoe movement; and Fig. 9 is a fragmentary view of a second form of thrust assembly valve, which affords another method of controlling speed of shoe movement.

Referring now to Fig. 1, an embodiment of my. invention is applied to a typical ironing machine comprising a suitable main frame or table ID, a buck H and a shoe 12, said shoe being carried by a substantially U-shaped carriage or arm I4 pivotally supported with respect to the frame as by pintles I5 mounte'din bearing lugs l6 at the base of a main hydraulic cylinder H. A handle l8 extends across the full length of shoe I2 and projects forwardly thereof on suitable brackets 20.

As is well known in the art, shoe l2 hasa smooth metallic pressing surface 2|, arranged to be heated by means such as electrical resistance units (not shown) embedded therein and having suitable thermostatic control. Structural details of a typical shoe and heating unit assembly are shown in the aforesaid Patent No. 2,135,266. The buck is supported by a suitable framework 22 fixed to the end of a piston within cylinder H, as later described. The cylinder is suitably supported by a flange structure 23 bolted or otherwise rigidly secured to the frame; |0.

Hydraulic power system Fig. 2 shows in full'line the ironer in readiness to have the work placed on the padded buck By means later detailed the shoe is brought forwardly and the buck is moved upwardly to their respective dotted line positions, in which the work then on the buck'is pressed against the heated shoe for ironing. The respective movements of the'buck and shoe are in synchronized relationship, and result from valve operation in the hydraulic power system. By valve control, hydraulic pressure is automatically made effective against the piston inthe shoe-operating cylinder 24, and then, at substantially the'com pletion of shoe-carriage travel, within the buck operating cylinder Cylinder I1 is the pressure source; in said cylinder is a fluid pressure generating system including an impeller 25 at the end of shaft 25 driven by a motor (not shown) arranged within an enclosed piston structure 21. The buck'is affixed to the upper end of the piston 21 by the previously noted frame 22. Piston 21 is provided with suitable piston rings 28, 29, the latter being carried by a composite piston head which includes a plate 33 from which extendsza valve structure 3|, illustratively a relatively short nozzle. When the buck is at rest, nozzle 3| is in seated relationship with a cooperating valve member comprising an outflow port 32 provided in cylinder wall 33. The seated nozzle valve is in substantially fluid sealing relationship therewith.

The head of piston 21 includes a plate 34 clamped between valve plate 30 and a flange 35 to which said valve plate is attached; plate 34 cooperates with a centrol web structure 36 to provide an impeller chamber. A ball thrust bearing 31 preferably spring mounted as shown supports the end of the impeller shaft 26. The cylinder I! has a predetermined charge of a suitable liquid, preferably a light oil, which under rest conditions attains the approximate level indicated by a dot-dash line in Fig. 4. The impeller receives the oil through the side wall openings 38, the central opening 40 in a baffle plate 4| and the central opening 42 in the web 36, and discharges it through the nozzle valve 31. With the hydraulic unit in the home position shown in Fig. 4, the oil under pressure is discharged directly to the channel 44 communicating with the cylinder 24. The bafiie 4| is advantageously supported upon angularly arranged diversion vanes 45 by tongues 46 struck inwardly from the wall of the. piston 2'1. A plurality of relatively small holes41 through the impeller 25 (see Fig. 7) relieves stresses beneath the impeller and the resultant axial thrust on the shaft 26.

After main control switch 48 has been closed, the pump motor may be energized by closing the normally open pedal switch 50, which may be suitably. carried in the lower frame structure as indicated in Fig. 1. It will be observed that so long as valve 3| remains seated, the driving force against piston 2! is equal only to the cross-sectional area of the nozzle valve '3] multiplied by the unitfluid pressure. Said area is so related to the area of piston 5| and its work loadthat the unit fluid pressure is insufiicient to raise piston 21 because of the movement of piston 5| within cylinder 24, said piston having a much greater area than than presented by the nozzle valve 3|. Piston 5| is initially opposed only by the relatively light spring 52 and the weight of shoe l2 and carriage M, the pistonrod 53 being pivotally connected to the latter by a suitable yoke 54, see Figs. 2'and 3. At the completion of travel of the shoe and carriage, as defined by the engagement of a stop 55 with the adjustable abutment 56 on main frame I0, full oil pressure Will react against the effective area of nozzle valve 3| to lift the 'pi'ston21 and the thereon carried buck. As the nozzle valve 3| unseats, oil pressure is made available within the chamber 51 against the full area of the piston head with resultant generation of full ironing pressure against the previously positioned shoe 2.

It. will be apparent that the foregoing construction provides a uniformly operating means of accurately synchronizing the operations of the buck and shoe, and that the buck'cannot be brought to ironing position until after the shoe has been placed. r

Uponopening the switch il by release of pressure'on the footpedal the rotation of the impeller will immediately cease and the buck piston will move downwardly under force of gravity assisted by the spring 58 afiixed to cars 6U,'6|' respectively'on the buck frame and main cylinder as shown in Fig. 2. The shoe arm M is urged into clockwise rotation of Fig. 2 by means of the pair of coil-springs 52, 62 disposed within the cylinder 24. Spring 62 is substantiallyheavier, and considerably shorter, than spring 52 andis supported within the piston 5| by relatively closely engaging the central neck thereof. Spring 52. is maintained in position by confinement between thecylinder head 63 and the piston 5| as shown in Fig. 4' At the extreme upward movemerit ofv the piston 5| the heavier spring '62 engages the cylinder head and is thereby compressed; the spring 52 is, of course, compressed during the entire movement of the piston. When oil pressure generation ceases, the combined recoil of the springs 52 and 62 urge the piston 5| sharply downwardly in its cylinder 21, rotating the arm l4 rapidly away from ironing position. After the downward movement ofpiston 5| has been sufiicient to disengage the spring 62, at which time it is contemplated that the shoe and arm will be in an overcenter position so as to add the force of gravity to the return movement thereoflthe relatively lighter spring 52 insures positive return of the arm and shoe to home position. Oil return from cylinder 24 is sufiiciently throttled reasonably to restrict the return travel, but shock. absorbing springs or the like may be applied to arm M, if desired. Oil returns to the cylinder I1 above the piston head through the channels 64 between the impeller blades, and the variously disposed piston head and pump casing openings previously described.

The second hydraulic system A further feature of the invention'comprises a hydraulic system interconnecting the cylinders l1 and 24 supplementary to the main'passage 44. This second system insures that the work devices operate in properly timedsequenoe, and provide apositive safety element in the event that the work device of cylinder 24 is held against operation. This supplementary system comprises a flow passage 66 opening into chamber 51 at 61 and into cylinder 24 at the spaced ports 68, 16. An advantage of casting cylinders l1 and 24 en bloc is the provision of the thick wall 65 within. which the passage 56 -may be formed. The necessity for tubular connections and fittings is thus avoided. The topmost port 12 which, as is evident. in Fig. 6 is above the maximum point of work travel of the piston 5|, is purely a vent passage to preventcompression of air within cylinder 24 as the piston rises, and through which may return to cylinder |1 oil which may have leaked into the cylinder 24 above the piston. The spacing of the ports 68, 10 is arranged with respect to the depth of the piston 5| and its upper limit of work travel so that near said upper limit both. ports are covered by the piston, and at the upper limit, port 68 is covered and port 10 is either wholly or in substantial part uncovered. It has previously been noted that the piston 5| "rises in advance of the piston 21 because. with the valve 3| in seated position the area of the pistn 5| is so much greater than the projected area of the nozzle or valve 3| that the reaction pressure of the fluid against said area is insufficient' to move-the piston 21. Piston 5 :ismoved; whereas piston 21 remains in home position.- The passage 66 and its several ports communicating. between cylinders 41 and 24, provide alow resistance path in the event of leakage at the valve 3| sufiic'ient to cause oil tofiow into the cylinder chamber 51. Therefore, even .under persistent leakage conditions pressure. will not generate below the piston head suflicient to thrust the piston assembly upwardly. Any such leake age would be small and would not rob the :cylin-. der 24 of its actuating pressure. Oil which entered the cylinder 24 above the piston 5| will be returned to themain cylinder l1 through the port 12 as the piston 5| reaches its uppermost position.

It is, of vcourse, apparent that the operation .of the shoe and buck may be stopped at any midposition by merely opening the switch 56.; 'However, it has been found that under; emergency conditions the operator may forget to operate the switch pedal and will instinctively push back against the shoe handle l3; to hold the shoe against further movement. Assuming that the impeller operation is maintaining oil pressure at such time,the,passage 66 provides a reliefcircuit enective so long as either of ports 68 or.:1.6 remains uncovered and piston 21 is permitted to raise the fraction of an inch necessaryv to un seat nozzle valve 3|. In this circumstance the operator may stop'the shoe l2 in midnight, the leverage provided by the shoe arm l4 being such that the operator may easily successfully oppose the force of piston 5| under the pressure condition existing in the system at that time. 3 The pressure fluid will enter passage through port 61, flow into cylinder 24 through either-of ports 68 or 101and return to cylinder I1, in which atmospheric pressure exists above the liquid level,'through port 12. As a matter of practical operation in an ironing machine having a padded buck, the yieldability of the padding makes it virtually impossible .to hold the buck against sufiicient movement to unseat valve 3|. Although it is perhaps unlikely that the necessity would arise except in certain industrial press applications of my invention, both pistons 21 and 5| may bestopped in mi'dflight because of the circulation path afforded by passage 66 and port 12.

Automatic timing The duct 66 serves also to insure the proper timing of the buck piston 21 as the shoe piston 5| reaches the upper limit of its stroke. As shown in Fig. 6 the length of piston 5| is such that port 68 will close before port 16 is uncovered. Near the end of travel of piston 5|, at which time nozzle 3| would not yet have unseated, oil .under pressure will flow from cylinder 24ybelow the piston 5| through the passages 10, 66, and 61 into cylinder |1 below the piston head in chamber 51 where sufficient pressure would then become available to unseat the nozzle, following, which lift of the buck piston 21 would proceed as previously described. I

It may be recognized that if desired, the cross sectional area of valve 3| may be made so small, or the initial tension of spring 58'so large or both of these elements cooperatively modified, that even when piston 5| reaches the end of its stroke and full fluid pressure is developed by the pressure generator said pressure acting on the effective area of the nozzle valve 3| will be insufii'cient to lift the buck piston 21. In such an arrangement the buck piston will not rise until the piston 5| reaches its Fig. 6nposition, as the result of which pressure fiuid will pass into chamber 5'! to exert against the large area ofpiston 21. and unseat the valve 3 I. i

As the valve 3| unseats the buck piston 2'! drives the buck up at maximum speed, because the. fluid is then being pumped through nozzle 3! directly into the chamber 51. It will thus be seen that the optimum timing of the buck and shoethat is, that the buck should not rise until after the shoe is positioned-is efiectively accomplished.

Speed control for shoe carriage Yet another feature of the invention resides in the provision of means to control the speed with which the shoe carriage comes into operating position. One method of speed control may be applied as indicated in Fig. 8, in which the pump motor circuit is provided with a variable resistance 15, adjusted to reduce the speed of the series wound impeller motor M to a predetermined level and correspondingly reduced oil discharge rate. Near the end of travel of the carriage to pressing position, the resistance is taken out of the circuit by a shunt circuit 13, controlled by a normally open contact switch H suitably mounted on the frame l so as to be engaged by the carriage [4 as it nears its operating position. For example, switch 11 may conveniently be mounted on the back plate 18 of the table [0, the actuating plunger 80 of said switch being in alignment with a suitable projection 8| on the carriage. The motor may be regulated at the factory or in'the field to operate at the speed necessary to provide the desired rate of pumping during the carriagetravel toward its operating position, whereupon at or suitably before the end of carriage travel the switch 11 operates to shunt out the resistance 16 and apply full voltage to the motor with resultant increase in operating speed and fluid delivery from the impeller. In this manner, the carriage arises relatively slowly to its operating position, and the buck comes up quickly to apply ironing pressure.

Speed control may also be accomplished by mechanical means such as a fixed, or suitably adjustable, orifice 33b communicating with the flow passage 44. Orifice adjustment may be accomplished, for example, by an adjustment screw 44a projecting through the screw plug 441), or in other equivalent means. When the thrust unit is in its lowermost position the restricted passage 33b throttles discharge from the impeller sufliciently to slow the upward movement' of piston as desired. a

Fig. 9 illustrates a ported sleeve valve 3m in lieu of the simple nozzle valve construction 3|. If desired, the sleeve valve may be of such length that it will not rise out of its valve seat during movement of buck ll into operating position. In any event as the "thrust unit'begins to rise following the attainment of full operating position of the shoe I2 the one or more ports 3 lb 'progressively expose and discharge-fluid from the impeller directly into the cylinder [1, thus vmaterially increasing the effective oil flow within cylinder l1 and correspondingly rapidly driving the buck piston assembly 21.

Thus, the several objectives ofv the invention may be accomplished. The valve structures represented by the nozzle 3| or the ported sleeve 31a provide self-timing-devices more certain in their operation, because actuallya part of one piston structure, than would be external valves which'would first direct fluid pressure to cylinder 24 and then in timed relationship, to cylinder II. It will be recognized, also, that the said valve structures are, in effect, auxiliary pistons of restricted area, in that the reaction of fluid pressure thereagainst effects the initial movement of the associated piston 21 so as to then permit the fluid pressure to act on the full area of said piston 21. These auxiliary pistons are nozzle-like or tubular only because the pressure generating means is, for reasons of compactness and the facility of storing the hydraulic fiuid in one of the cylinders, a part of the piston structure in said cylinder; an external pressure generator communicating directly with the main fluid passage 44 would obviously require that the auxiliary piston have a closed end of suitable area.

While I have shown a particular embodiment of my invention, it will be understood, of course, that I do not wish to be limited thereto since many modifications may be made; and I therefore contemplate by the appended claims to cover any such modifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. An ironing machine comprising, in combination, a main frame; a pressing member supported therein for linear movement; a second pressing member; a carriage for said second member, said carriage being movable relative to said frame to a position in which its pressing member is in cooperative alignment with the first named member; a cylinder fixed with respect to said frame and having piston means for moving said carriage into pressing position; a second cylinder fixed with respect to said frame and having piston means for moving the first pressing member into operative position, means responsive to external control to generate fluid pressure within said second cylinder; a discharge port from said cylinder; a flow passage communicating between said discharge port and said first named cylinder, the piston in said cylinder having an area responsive to the generated fluid pressure to effect immediate movement of said carriage; and a nozzle valve carried by said second piston means and normally seated against said discharge port, the projected area of said valve exposed to the fluid pressure being much less than the area of either piston and insufiicient with respect to the available fluid pressure to move its associated piston until the completion of movement of the first piston, whereupon the reaction pressure against said exposed valve area will efiect movement of its associated piston sufiicient to unseat the valve and make fluid pressure available against the area of said second piston to drive the same within its cylinder.

2. An ironing machine comprising, in combination, a main frame; a pressing member supported therein for linear movement; a second pressing member; a carriage for said second member, said carriage being movable relative to said frame to a position in which its pressing member is in cooperative alignment with the first named member; a cylinder fixed with respect to said frame and having piston means connected to said carriage for moving said carriage into pressing position; a second cylinder fixed with respect to said frame and having a piston connected to said first named pressing member to move the same into pressing position; means carried by the second piston and responsive to external control'to generate fluid pressure; a discharge port from said cylinder; a flow passage communicating between said discharge port'and said first named cylinder; a nozzle valve projecting from the head of the second piston and concentric with said discharge port, said nozzle valve having an end area much less than the areaof either piston head; means for biasing said second piston to normally seat the nozzle valve within the discharge port, whereby the eifective fluid pressure during movement of said first named piston is insufiicient in view of the limited area of said nozzle valve to move the associated piston; and means for stopping said-first named piston at a predetermined point to permit the resulting pressure increase within the flow passage to unseat the nozzle valve and make fluid pressure available against the head of the second piston to move the same within its cylinder 3. An ironing machine, including cooperating press members individually movable relative to each other to press materials therebetween; and a hydraulic system for moving the respective press members, comprising a cylinder individual to each member and having apiston for driving the same, said cylinders being fixed relative to their associated press members and one of said cylinders having a pre-established liquid content; a discharge-port from said one cylinder; a flow passage communicating directly between said discharge port and said second cylinder; a motor driven pump disposed within the piston of said first cylinder and having a discharge chamber carried by the piston head, said chamber including a nozzle extending therefrom and seatable within said discharge port; means for yieldably holding said piston at the discharge end of said cylinder with the nozzle seated so as to discharge liquid under pressure directly into said port to supply liquid under pressure to said flow passage for exertion against the second piston to drive the same, the area of said nozzle exposed to the reaction pressure of said liquid during motion of said second piston being such that the propulsive eifort against said nozzle is insuiilcient to unseat the same; and means for interrupting movement of said second piston and its associated press member at a predetermined point, whereupon. the resulting reaction pressure unseats the nozzle to make hydraulic pressure available within the first cylinderto move the piston thereof.

4. An ironing machine having cooperating press members individually movable relative to each other to press materials placed therebetween; and a hydraulic system for moving the respective press members in pre-established timed relationship, including a cylinder individual to each member and having a piston for driving the same, said cylinders being fixed relative to their associated press members and one of said cylinders having a pre-established liquid content; a discharge port from said one cylinder; a flow passage communicating directly between said port and the second cylinder; a motor driven pump carried by the piston in the first cylinder and effective under external control to create fluid pressure; a tubular 'auxiliary piston member extending from the outlet of said pump and fixed relative to the head of said piston; means for normally seating said auxiliary piston within said cylinder discharge port to discharge liquid under pressure from said drive the same, the area of said auxiliary piston exposed to thereaction pressure of saidliquid during motion of said second piston being such that the propulsive effort against said auxiliary piston is insufficient to unseat the same; and means for interrupting movement of said second piston and its associated press member at a predetermined point, whereupon the resulting reaction pressure unseats said auxiliary piston to make hydraulic pressure available with the first cylinder to move the piston thereof.

5. An ironing machine, comprising, in combination, a main frame, a pressing member supported therein for linear .movement, a second pressing member, a carriage for said second member, said carriage being supported relative to said frame and movable to a position in which its pressing member is in cooperative alignment with the first named member, a cylinder fixed relative to said frame and having piston means for moving said carriage to bring its associated pressing member into operative position, a second cylinder fixed relative to said frame and having piston means for moving said first pressing member into operative position, means carried by the piston of said second cylinder for generating fluid pressure for driving the respective pistons, and valve means carried by said second pitson for delaying the imposition of fluid pressure on said second piston means sufficient to drive the same until after the first named piston means has substantially completed its stroke to place the carriage and therewith associated pressuring member in operating position.

6. An ironing machine, comprising, in combination, a main frame,,a pressing member supported therein for linear movement, a second pressing membena carriage for, said second member, said carriage being supported relative to said frame and movable to a position in which its pressing member is in cooperative alignment with the first named member, a cylinder fixed relative to said frame and having piston means for moving said carriage to bring its associatedpressing member into operative position, a secondcylinder fixed relative to said frame and having piston means for moving said first pressing member into operative position, means for generating fluid pressure for driving the respective pistons, and means carried by said second piston for delaying the imposition of fluid pressure necessary to drive said. second piston until after the first named piston means has substantially completed its stroke to place the carriage and therewith associated pressing member in operating position.

'7. An ironing machine, comprising, in combination, a main frame, a pressing member supported therein for linear movement, a second pressing member, a carriage for said second member, said carriage being supported relative to said frame and movable to a position in which its pressing member'is in cooperative alignment with the first named member, a cylinder fixed relative to said frame and having piston means for moving said carriage to bring its associated pressing member into operative position, a second cylinder fixed relative to said frame and having piston means for moving said first pressing member into operative position, means for generating fluid pressure for driving the respective piston means, and a valve controlling flow of fluid pressure to said second cylinder operative to delay the imposition of fluid pressure necessary to drive said second piston means until after the first named piston means has substantially completed its stroke to place'the carriage and 11 therewith associated pressing member in operating position. t t V 8. A hydraulic power system comprising a plurality of cylinders having pistons therein to operate external devices in timed'relationship;

said chamber andslidable within said discharge port in relatively tight relation with the wall thereof; and means for yieldably holding said tubular member within said port, whereby upon operation of said pressure generator'liquid under pressure is discharged through said port to the other of said cylinders to exert motive'pressure on'the piston therein, the area of said tubular member exposed to the reaction pressure of the liquid being so much smaller than the piston area of the other of said cylinders that said tubular member will move outwardly of said discharge port'to admit fluid pressure into its associated cylinder only when movement of the piston in said other of said cylinders is abnormally opposed.

9. man ironing machine having a main frame and a pair of cooperating pressing members movably mounted therein, a hydraulic power system for moving said members into operating position in timed relationship, comprising a hydraulic cylinder individual to each pressing member and having a piston for the operation thereof, one of said cylinders having a predetermined liquid content; externally controllable means contained within the piston of said cylinder and supplied from said liquid content for generating fluid pressure to move said pistons within their respective cylinders; a fiow passage between said one cylinder and the other cylinder for transmitting said fluid pressure from the said one cylinder to the said other cylinder; and means carried by the piston in said one cylinder for initially restricting the area of fluid pressure effort on such piston to an extent whereby the fluid pressure generated therein is insufiicient to move it until motion of the piston in said other cylinder has been arrested.

10. A hydraulic power system comprising, a first cylinder having a predetermined content of liquid; a piston therein; means directly associated with said piston and served by said liquid content to generate hydraulic pressure, said means having a tubular member defining the discharge therefrom; a second cylinder; a piston therein; work devices connected to therespective pistons to be operated thereby; a conduit connecting said cylinders for the operation of said second piston by pressure flow from said first cylinder; a valve port in a wall of said first cylinder defining the entrance to said conduit; and means for biasing said first piston to a home position in which said tubular discharge member is seated relative to said valve port to discharge pressure fluid directly into said conduit to the substantial exclusion of discharge into said first cylinder, the efiective area of said tubular member being so related to the area of said second piston that until movement of the latter is abnormally restrained the reaction pressure against said nozzle will be insufficient to unseat said tubular member'to permit the generation of pressure 12 within said first cylinder sufiicient to move the piston thereof. l

11. A hydraulic power system comprising, a first cylinder having a predetermined content of liquid; a piston therein; means associated with said piston and served by said liquid content to generate hydraulic pressure, said means having an outflow casing defining a discharge orifice; a second cylinder; a piston therein; work devices connected to the respective pistons to be operated thereby; a conduit connecting said cylinders for the operation of said second piston by pressure flow from the first cylinder; a valve port in a wall of said first cylinder defining the entrance to said conduit; a second conduit extending from said first cylinder beneath the piston thereof to enter the second cylinder at a sidewall port arranged to be temporarily closed by traversal of the second piston thereacross; and means for biasing said first piston to a home position in which the discharge means of said pressure generating means is in seated relationship with said valve port to discharge pressure fiuid directly into said first conduit to the substantial exclusion of discharge against said first piston, the efiective area of said second piston being so related to the first piston biasing means that said discharge means will remain seated until after the second piston has been driven by the said sidewall port to make available pressure flow from the second cylinder to the first cylinder'to exert motive pressure thereagainst.

12. A hydraulic power system comprising a plurality of cylinders having pistons therein to operate external devices in timed relationship, a discharge port from one cylinder communicating with the other of said cylinders, said one cylinder having a predetermined liquid content; externally controllable means contained within its piston for generating fluid pressure, said pressure generating means including a rigid outflow nozzle fixed relative to the head of said piston and engageable with said discharge port in close wall to wall relationship therewith; means for yieldably holding said nozzle within said port whereby upon operation of said pressure generator liquid under pressure is discharged through said port to the other of said cylinders to exert motive pressure therein, the area of said'nozzle exposed to the reaction pressure of the liquid being so much smaller than the piston 'area of the other of said cylinders that said nozzle will move relative to said orifice to admit fiuid pressure into its associated cylinder only when movement of a piston in the other of said cylinders is abnormally opposed; and means for relieving fiuid pressure in the circumstance of abnormal opposition to full movement of said other cylinder piston, comprising a passage extending from said first cylinder at a point between the piston head and the discharge port to a point of entry at the other cylinder at which it will be covered by the piston therein substantially at the termination of said piston travel.

13. A hydraulic power system comprising a plurality of cylinders having pistons therein to operate external devices in timed relationship;

substantially fluid-tight relationship therewith; means for yieldably holding said nozzle within said port whereby upon operation of'said pressure generator liquid under pressure is discharged through said port to the other of said cylinders to exert motive pressure therein, the area of said nozzle exposed to the reaction pressure of the liquid being so much smaller than the piston area of the other of saidcylinders that said nozzle will move relative to said orifice to admit fluid pressure into its associated cylinder only when'movement of a piston in the other of said cylinders is abnormally opposed; and means for relieving fluid pressure in the circumstance of abnormal opposition to full movement of said other cylinder piston, comprising a passage extending from said first cylinder at a point between the piston head and the discharge port to a point of entry at the other cylinder where the pressure at all times prior to substantially full movement of the piston therein is substantially less than the fluid pressure against said piston.

14. A hydraulic power system comprising a plurality of cylinders having pistons therein to operate external devices in timed relationship, a

discharge port from one cylinder communicating with the other of said cylinders, said one cylinder having a predetermined liquid content; externally controllable means contained within its piston for generating'fluid pressure, said pressure generating means including a rigid outflow nozzle fixed relative to the head of said piston and slidable within said discharge port; means for yieldably holding said nozzle within said port whereby upon operation of saidpressure generator liquid under pressure is discharged through saidport to the other of said cylinders to exert motive pressure therein, the area of said nozzle exposed to the reaction pressure of the liquid being so much smaller than the piston area of the other of said cylinders that said nozzle will move relative to said orifice to admit fluid pressure into its associated cylinder only when movement of a piston in the other of said cylinders is abnormally opposed; and means for relieving fluid pressure in the circumstance of abnormal opposition to full movement of said other cylinder piston, comprising a flow passage efiective upon withdrawal of the nozzle from said orifice in such circumstance to divert oil flow to a receiver from which it may be returned to the pressure generation cylinder.

15. In an ironing machine having a main frame, a pressing member supported therein for linear movement, and a second pressing member supported on means for moving said second member from a rest position to a position in cooperative alignment with said first member, a hydraulic system for moving said pressing members into operating position in timed relationship, comprising a first hydraulic cylinder fixed withinsaid main frame and having a piston for moving said first pressing member; a second hydraulic cylinder fixed relative to said frame and having a piston for moving said second pressing member; a main fluid conduit system interconnecting said cylinders, said conduit system including an oriflce entering said first cylinder'at one end thereof; an auxiliary piston fixed to the first-cylinder piston and projecting therefrom into said orifice; means for releasably holding said first piston at the end of its cylinder with the auxiliary piston occupying said orifice; means communicating with said main conduit system for generating fluid pressure therein to exert motive power against the respective pistons exposed thereto, the area of said auxiliary piston being so much smaller than the area of the second piston as to be ineffective to move its thereto afiixed I main piston until movement of said second piston under fluidpressure has been interrupted; and a second fluid passage communicating from the first cylinder between the main piston head and the orifice to the second cylinder at a point just prior tov the limit of work travel therein. so as to divert fluid under pressure from said second cylinder to the first cylinder to act aganist the main piston therein and thereby supplement the force applied against the auxiliary piston.

l6. Inan ironing machine having a main frame and a pair of cooperating pressing members movably mounted therein, a hydraulic system for moving said members into operating position in timed relationship, comprising a hydraulic cylinder individual to each pressing member and having a piston for operation thereof; a relatively short discharge port from one cylinder communicating with the other cylinder, said one cylinder'having a predetermined liquid content above the piston thereof; externally controllable means contained within said piston and supplied from said liquid content for generating fluid pressure sufficient to move the said pistons within their respective cylinders; a hibular, outflow member *of'relatively small end wall area fixed to; the piston of said pressure-generation cyl-' inder and providing a main outlet from said pressure generation means, said tubular member entering said discharge port; means yieldably urging said pressure generation piston toa position in which its said tubular member is within said port, whereby upon operation of said pressure generator liquid underpressure is discharged substantially wholly through said port to the second named cylinder" to exert motive pressure on the piston therein; a passage'communicating from the first cylinder between the piston head therein and the discharge port to the second cylinder at a point which will be traversed by the secondcylinder piston justprior to the end-of its normal work stroke to afiord circulation of pressure fluid from said second cylinderto said first cylinder; and means for stopping said second cylinder piston at the end of its said work stroke.

17. In an ironing machine-having a main frame and a pair of cooperating pressing members movably mounted therein, a hydraulic power system for moving said members into operating position in timed relationship, comprisinga hydraulic cylinder individual to each pressing member and having a piston for the operation thereof, one of said cylinders having a predetermined liquid content; externally controllable means contained of said piston to said fluid pressure following a predetermined travel of the piston in the second cylinder.

18. In an ironing machine having a main frame and a pair of cooperating pressing members movably mounted therein, a hydraulic power system for moving said members into operating position in timed relationship, comprising a hydraulic cylinder individual to each pressing member and having a piston for the operation thereof; one of' said cylinders having a predetermined liquid content; externally controllable means contained within the piston of said cylinder and supplied from said liquid content for generating fluid pressure to move said pistons within their respective cylinders; a flow passage between said cylinders for transmitting said fluid pressure from thefirst to the second cylinder; means for initially restricting the area of fluid pressure effort on the first piston to an extent whereby the fluid pressure generated therein is insuflicient to move said piston until motion of the second piston has been arrested; 'means comprising a bypass conduit communicating between said cylinders for relieving pressure therein in a circumstance wherein the second piston is held against its full work travel, and means including the same conduit for exposing the full area of said first piston to said fluid pressure after a predetermined travel of the second piston.

19. In an ironing machine having a main frame and a pair of cooperating pressing members movably mounted therein, a hydraulic power system for moving said members into operating position in timed relationship, comprising a hydraulic cylinder individual to each pressing member and having a piston for the operation thereof, one of said cylinders having a predetermined liquid content; an electric motor driven pump contained within the piston of said cylinder and supplied from' said liquid content for generating fluid pressure to move said pistons within their respective cylinders; a flow passage between said cylinders for transmitting said fluid pressure from the first to the second cylinder; means carried by the first piston for initially restricting the area of fluid pressure effort on the first piston to an extent whereby the fluid pressure generated therein is insufficient to move said piston until the motion of the second piston is arrested; means carried by said frame for limiting the travel of said second piston; and electric circuit means energized by said second piston at a predetermined point of its travel to increase the output rate of said pump.

20. In an ironing machine having a main frame" and a pair of cooperating pressing members movably mounted therein, a hydraulic power System for moving said members into operating position in timed relationship, comprising a hydraulic cylinder individual to each pressing member and having a piston for the operation thereof, one of said cylinders having a predetermined liquid content; an electric motor driven pump contained within the piston of said cylinder and supplied from the liquid content thereof togenerate fluid pressure to move said pistons within "their respective cylinders; a flow passage between said cylinders for transmitting said fluid pressure from the first to the second cylinder; means for initially restricting the area of fluid pressure eflort on the first piston -toan extent whereby .the fluid pressure generated therein is insufiicient to move said piston until the motion of the. second piston is arrested; an electric control circuit for adjustably reducing line-voltage to said pump motor to reduce the speed and corresponding pump output to a predetermined value; a circuit shunting out said control circuit; a normally open switch in said shunt circuit; and means for closing said switch at a predetermined point to shunt out said control circuit to increase the speed and output of saidpump. Y

21.' In an ironing machine having a main frame and a pair of cooperating pressing members movably mounted therein, a hydraulic power system for moving said members into operating position in timed relationship, comprising a hydraulic cylinder individual to each pressing member and having a piston for the operation thereof; means including an externally controllable pump contained within the piston of one of said cylinders and supplied from a liquid reservoir therein for generating fluid pressure to move said pistons within their respective cylinders; a flow passage between said cylinders for transmitting said. fluid pressure from said one cylinder to the other; means including a ported tubular pump discharge member afiixed to the piston in said one cylinder and extending intosaid flow passage in tight slide able engagement therewith for initially restricting the area of fluid pressure effort on said :piston toan extent whereby the fluid pressure generated therein is insufiic-ient' to move said piston until motionof the second piston has been arrested; and means including side wall ports in said tubular member for causing rapid flow of oil under pressure from said passage into said one cylinder after an initial movement thereof suficient to withdraw said side wall ports from said flow passage.

ROBERT SHEAHAN. 7

REFERENCES CITED The following references are of record in the file of this patent: V

UNITED STATES PATENTS Barifii July 5, 1949 

